From be22520dc2bc13d2cfa59266f55776889f5a2775 Mon Sep 17 00:00:00 2001
From: Dodji Seketeli <dodji@redhat.com>
Date: Tue, 13 Nov 2012 16:07:39 +0000
Subject: PR c++/54466 - ICE with alias template which type-id is const
 qualified

Consider this short example:

    template<typename T>
      struct X { };

    template<typename T>
      using Y = const X<T>;

    using Z = Y<int>;

G++ crashes in lookup_class_template_1 while trying to build the alias
template instantiation Y<int>.

I think this is indirectly due to the fact that that
lookup_class_template_1 can now yield a const qualified type like
'const X<T>'.

As a consequence, the code in lookup_template_class_1 that was trying
to access the TYPE_STUB_DECL field of the result of
lookup_template_class_1 should now be adjusted to access the
TYPE_STUB_DECL of the main variant of the resulting type instead (and
that is TYPE_MAIN_DECL); because qualified types (constructed with
build_qualified_type) have their TYPE_STUB_DECL set to NULL.

Fixed thus and tested on x86_64-unknown-linux-gnu against trunk.

gcc/cp

	PR c++/54466
	* pt.c (lookup_template_class_1): TYPE_STUB_DECL should be
	accessed on the main variant of the type.

gcc/testsuite/

	* g++.dg/cpp0x/alias-decl-26.C: New test file.

In the example of this patch, g++ crashes when trying to build the
alias template Y<int

From-SVN: r193479
---
 gcc/cp/ChangeLog                           |  6 ++++++
 gcc/cp/pt.c                                |  4 ++--
 gcc/testsuite/ChangeLog                    |  5 +++++
 gcc/testsuite/g++.dg/cpp0x/alias-decl-26.C | 10 ++++++++++
 4 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/cpp0x/alias-decl-26.C

(limited to 'gcc')

diff --git a/gcc/cp/ChangeLog b/gcc/cp/ChangeLog
index cb861cb..0f23cbc 100644
--- a/gcc/cp/ChangeLog
+++ b/gcc/cp/ChangeLog
@@ -1,3 +1,9 @@
+2012-11-13  Dodji Seketeli  <dodji@redhat.com>
+
+	PR c++/54466
+	* pt.c (lookup_template_class_1): TYPE_STUB_DECL should be
+	accessed on the main variant of the type.
+
 2012-11-12  Ed Smith-Rowland  <3dw4rd@verizon.net>
 
 	* parser.c (cp_parser_objc_class_ivars):
diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c
index 50d12b0..802c79b 100644
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -7372,9 +7372,9 @@ lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
       if (CLASS_TYPE_P (template_type))
 	{
 	  TREE_PRIVATE (type_decl)
-	    = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
+	    = TREE_PRIVATE (TYPE_MAIN_DECL (template_type));
 	  TREE_PROTECTED (type_decl)
-	    = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
+	    = TREE_PROTECTED (TYPE_MAIN_DECL (template_type));
 	  if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
 	    {
 	      DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 1eba36d..e82a88f 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-11-13  Dodji Seketeli  <dodji@redhat.com>
+
+	PR c++/54466
+	* g++.dg/cpp0x/alias-decl-26.C: New test file.
+
 2012-11-13  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* gcc.target/i386/avx256-unaligned-load-2.c: Requre !ia32
diff --git a/gcc/testsuite/g++.dg/cpp0x/alias-decl-26.C b/gcc/testsuite/g++.dg/cpp0x/alias-decl-26.C
new file mode 100644
index 0000000..dd4cc02
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp0x/alias-decl-26.C
@@ -0,0 +1,10 @@
+// Origin: PR c++/54466
+// { dg-do compile { target c++11 } }
+
+template<typename T>
+  struct X { };
+
+template<typename T>
+  using Y = const X<T>;
+
+using Z = Y<int>;
-- 
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